private website for chessengine-tests

SALC was made for engine-testing and engine-tournaments (all engines must use SALC openings, SALC is not for playing versus other books!!!). Download the SALC V5 package here

SALC means "S"hort "A"nd "L"ong "C"astling: white and black castling to opposite sides (if white played 0-0, black played 0-0-0. If white played 0-0-0, black played 0-0)), both queens still on board. No double games. Evaluation of Komodo 11.2.2 at the end of the opening-line (60 seconds thinking-time, 3 cores, 2048MB Hash) in an interval of [-0.6,+0.6] and not 0.00.

When using SALC-openings, the chance for attacks towards the opponent king is much higher than using normal opening-books. Because of this, computerchess using SALC openings, will bring more action and fun to watch (and a measureable lower number of draws), because the faster the computers get, the higher the quality of computerchess get and the higher the draw-rate in engine-engine-matches get...so the computerchess is in danger to die the "draw-death" in the near future. So, using SALC openings will give computerchess a future beyond playing only draws or using strange and incorrect gambit-openings for a lower draw-rate!

If anybody doubt that the draw-death of computerchess will come, just take a look at Andreas Strangmuellers excellent website:

Here you can see, how much the draw-rate is rising, when the thinking-time (increasing PC-speed in the future is equivalent to longer thinking-time today, of course) is raised. From 49.2%draws with bullet-speed (Komodo 9.3 (singlecore, only (!)) in selfplay with 20''+0.2'' vs. 10''+0.1'') to 78.8% draws with long thinking-time (5120''+51.2'' vs. 2560''+25.6'') (3000 games each testrun (!))

All SALC V5 data was filtered out of the BigDatabase 2018 (7.2 million human games)

What is new in SALC V5 (compared to older SALC V1 - V3) ? SALC V5 contains half-closed SALC-positions, only. And that leads to measureable lower draw-rates, compared to older SALC-versions - take a look at the testing-results below. So, it is strongly recommended to use the new SALC V5 openings from now, only and not the older SALC-versions !!!

For this half-closed (hc) SALC positions, following conditions had to be true (in the endposition of each opening line):

1) SALC (= white and black castled to different sides of the chessboard)
2) both Queens still on board.

using only (1+2), getting the "normal" SALC-positions, which were used for older SALC (V1 – V3).

These are the half-closed filters:

3) On d-line or e-line at least one white and one black pawn (=one of both center-lines closed)
4) no pawn-capture on the center-squares (e4,d4,e5,d5) possible (means: not allowed: (white pawn on e4 and black pawn on d5) or (white pawn on d4 and black pawn on e5) - so, the position cannot get fully open after 1 or 2 played moves by the engines.
5) no pawn-free d-line, when both queens are on d-line. So, the queens cannot capture each other after 1 or 2 played moves by the engines.

The idea is, that in these half-closed positions, the probability of fast and many capturing-moves is much lower, so it should took more time (and moves) to reach drawish endgame-positions. So, the probability of an interesting and long midgame should get higher...

- SALC V5 opening-book for Fritz, Shredder and Arena (3 folders) (each book containing more than 200000 moves). Take a look at the booksettings.jpg-picture in each folder, for the correct booksettings!!!

- 25000 opening-lines, the books were made of, as PGN (10 moves deep games, all ending as draw) and EPD (endposition of each line) (SALC_V5_hc_10m.pgn and SALC_V5_hc_10.epd)

- 2 smaller Testsets (PGN and EPD files) in the folder Testsets:

a) 5000 SALC V5 full-closed and 10 moves deep positions, filtered out of the 25000 opening-lines file. The testset contains only positions with an evaluation-interval of [-0.31,-0.53] and [+0.30, +0.53]
b) 500 SALC V5 full-closed and only 8 moves deep positions with an evaluation-interval of [-0.39,-0.30] and [+0.30, +0.39]. Complete separate filtered and calculated with 180 seconds per endposition (instead of 60 seconds for the big half-close openings)

Full-closed means, following conditions had to be true (in the endposition of each opening line):

1-5 (SALC half-closed filters (see above)) and additional:

6) On d-line or e-line at least one white and one black pawn (=one of both center-lines full-closed) and on the other center-line at least one pawn (=other center-line at least half-closed).
7) no pawn-capture on or into the center-squares (e4,d4,e5,d5) possible (means: not allowed: (white pawn on e4 and black pawn on d5) or (white pawn on d4 and black pawn on e5) or (white pawn on d3 and black pawn on e4) or (white pawn on e3 and black pawn on d4) or (white pawn on e5 and black pawn on d6) or (white pawn on d5 and black pawn on e6)) - so, the position cannot get fully open after 1 or 2 played moves by the engines.
8) no complete “pawn-blocked“ center with “french-closed“ pawn-patterns. Means: not allowed are
(white pawns on d3 & e4 and black pawns on d4 & e5) or
(white pawns on e3 & d4 and black pawns on e4 & d5) or
(white pawns on d4 & e5 and black pawns on d5 & e6) or
(white pawns on e4 & d5 and black pawns on e5 & d6)
9) White queen only allowed on (c1, d1, e1, f1, c2, d2, d3, e2, f3) and black queen only allowed on (c8, d8, e8, f8, c7, d7, d6, e7, f6).

For all serious testwork, I recommend using the small 500 SALC V5 full-closed (and only 8 moves deep) positions. Because a lot more filters were used (see above) and Komodo calculated all endpositions with 180 seconds (not only 60 seconds) thinkingtime. And the results in the tests (see testing results at the end of this ReadMe-file) are the best, I have ever seen (lowest draw-rate, widest Elo-range results). If 500 positions are not enough, use the 5000 SALC V5 full-closed and 10 moves deep testset for your testwork.

Testing results of Opening-Sets (SALC, FEOBOS, Noomen Gambits...)

Here some testing-results of SALC compared with the standard 8move-openigset used in the Stockfish-framework (all played games: 5'+3'', singlecore, 256MB Hash, no endgame-bases, no ponder, both engines with Contempt=+15)

Here the result of FEOBOS openings (v20 (official release version), contempt 5 and played in Gauntlet-mode, so the best 500 positions of FEOBOS are played and repeated with reversed colors (the positions in the FEOBOS.epd files are sorted by "quality" (whatever that means)(=highest possible contempt, should deliver lowest possible draw-rate, Feobos can do)))

Download the games of the FEOBOS, Noomen openings and both SALC V5 testruns here

Take a look at the draw-rates !! Must I say anything more?!?

Especially the full-closed 500-position opening set result is absolute amazing! Take a look, how wide the Elo-range of the result is (66.5% - 33.5%, instead of 60.3% - 39.7% with standard openings). And the number of draws was lowered -25% (634 to 477 draws in 1000 games, each testrun) compared to the standard Stockfish framework openings!

The 100 Noomen TCEC Superfinal (Season 9+10) openinglines have a very good result, too! But mention, that 30 of these 100 positions are SALC-positions or positions, in which castlings into SALC-positions are quite likely in the first few moves to play by the engines. And 100 positions are a very, very small openings-set - it cannot be used for huge tournaments or for creating an openingbook.

Take a look at the average game-duration: Using the Stockfish standard openingset, the average game-duration was 1036 seconds. And using SALC V5 openings, the average game-duration was only 925 seconds. So, nearly 11% less PC-time was needed, using SALC, which means, in the same time, using SALC, around 11% more games can be played on a PC in the same time!!

And mention, that the scores of the engines are not getting closer to 50%, using SALC. The Elo-differences are not getting smaller. In fact, they are getting measureable higher(!), which proofs, that SALC does not contain a lot of lines, which are leading to a clear advantage (and easy wins) for white or black (easy wins for white or black would push all engine-scores towards 50% and would make Elo-differences smaller, because each engine would play such positions from time to time). And the bigger Elo-differences, using SALC, make the results statistical more reliable.

And, finally, a lot of people said, that SALC-positions are only a small part of all possible chess-openings (thats true), and that using SALC-openings for engine-play will lead to distorted results – and that is not true. Here the proof:

Using the new HERT openings-set (by Thomas Zipproth) for my Stockfish-testing was a great opportunity to compare the gamebases played with HERT (contains positions selected from the most played variations in Engine and Human tournaments) and played with my SALC openings So, here the results. Both gamebases were played with 3'+1'', singlecore, 512 MB Hash. The only difference was the opening-set (HERT / SALC)... 2x 15000 games (!)

1) SALC lowers the draw-rate a lot (35.8%) , compared to the HERT openings-set (42.8%) - mention, that the HERT-set was optimized for a low draw-rate. Thomas Zipproth has chosen only lines, which were not too drawish. Using other "classical" openings-sets should lead to a higher draw-rate, than using HERT.

2) The order of rank is the same for all engines in both gamebases = no distorted results playing SALC.
3) The scores of the engines are not getting closer to 50%, using SALC. The Elo-differences are not getting smaller (in fact, they are getting higher! (Elo-differences rank 1 to 6: 320 Elo using HERT, but 347 Elo using SALC), which proofs, that SALC does not contain a lot of lines, which are leading to a clear advantage (and easy wins) for white or black. And bigger Elo-differences make the results statistical more reliable.
4) SALC lowers the average game duration around 10%. That means, that in the same time, +10% more games can be played, which leads to statistical more valuable results in the same time.